Fibrous composition and process for making the same.



G. A. HENDERSON.

FIBROUS COMPOSITION AND PROCESS FOR MAKING THE SAME.

APPLICATION FILED FEB. 12. I9I6.

Patented May 7,1918

E% PATENT @FFIQE.

FIBBOUS GOM?OSITION AND PROCESS FOR MAKING THE SAME.

To all whom it may concern:

Be it known that I, GEORGE A. HENDER- SON, a citizen of the UnitedStates, residing in Highland Villa, at St. Albans, in the county ofKanawha and State of West Virginia, have invented certain new and usefulImprovements in Fibrous Compositions and Processes for Making the Same,of which' the following is a clear, full, and exact description.

The invention relates to a new process for rendering woody particlesunnatural and restoring them to their initial density and consistencyina preserved state and to the manner of their incorporation with apreservative-binder in forming building and paving structures of theclass referred to in my issued United States Patent No. 1,040,321, of1912, and my pending applications, Number 874,934, filed November 30,1914, and Xumber 64,285, filed November 30, 1915. While the latterrepresent substantial improvement in the art, my present invention isbased on my discovery that superior structures are more economicallyobtainable by substantial departure from the processes heretoforedisclosed. Also, while in my former processes I use the waste wood fromtannic acid and dye manufacturers, in whose process the wood isdenatured, in the present process an incidental object is to reduce tocommercial use the great quantity of hardwood heretofore discarded aswaste culls of veneer plants, in which the wood is merely softened bywater before shearing it into sheets of uniform thickness.

Hereinafter, in relation to this invention, by particles I mean woodyparticles of not exceeding in uniform thickness, shredded into variouslengths and breadths graduating in irregular area aggregating 1" x i"down to the thickness of the particles, the edges of which are beveled,ragged and torn to tatters in being shredded from thesheets of the woodsheared from the log, measured in predetermined quantities of each sizein regularly descending gradations from the largest to thoseapproximately a" x forty per cent, those from x "'to the thicknessthereof to which is added 10% of particles reduced in size from thegreatest thickness to those of dimensions corresponding to the thicknessof the ragged edges of the particles, all impalpable dust being entirelyeliminated.

Specification of Letters Patent.

Patented May i913.

Application filed February 12, 1918. Serial No. 77,953.

By fibers I mean those longitudinal strands of tougher consistence thanthe cellular tissue by which they are surrounded in their natural state;by pores I mean those spaces within the wood particles walled by thefibers composing the particle, whether filled or unfilled; by voids Imean spaces or interstices between the separate woody particles; bymoisture I mean a quantity of water in excessof that required tomaintain the identity of the fibers as such; by normal I refer to thenatural state or size of the particles and the natural volume of theirpores before abnormal enlargement or other treatment herein referred to;as well as to the consistency and volume of the binding preservativehereinafter described, when cold, and before expanded or subjected tothe treatment herein prescribed; by bitumen I mean a compound of pitch,natural or artificial asphalt of bituminous nature used in pavingstructures, and known to the trade; by penetration I mean the UnitedStates standard measure of consistency and density of bitumen as appliedto paving structures.

In practice I have discovered that durability of such compositions isincreasedvby the present process in which the particles are morecompletely, efiiciently and economically denatured, ore-expanded,impregnated, contracted, bound and compressed, the graded particles moreuniformly mixed and advantageously positioned in the mass, and theimpregnating binder more thoroughly and uniformly disseminatedthroughout the mass by simultaneous accomplishment of these objects,than in the manner disclosed v in the prior art, as distinguished fromwhich the particles are, in the present process, not heated, their sapand pulp not extracted, they are not saturated with water, nor are theyexpanded, then dried and contracted before impregnation with theirpreservativebindor. On the contrary these steps are more simplv andeffectively taken simultaneously. that of water saturation beingentirely eliminated. The destructive distillation of the cellulartissues of the particles, and the expelling of their sap and moisturecontent. together with maximum expansion of the pores and the consequentdevelopment of maximum absorbing efficiency of the particles, resultsfrom my employment of extreme heat. above the normal carboniztheminimum, l have ing point of the bitumen, as well as that oi the wood,sustained throughout such iniprcgnation oi the particles by theirbinder, and during partial compression of the mass, as and for thepurposes hereinafter dcscribed.

l have discovered that such heat, in combination with substantial vacuumcreated Within the chamber containing it, is essential to sufficient"fluidity of a quantity of bitumen in exccss of that required in thecompleted product, which excessive quantity is temporarily neediul in myprocess for the purposes hereinafter described. and that such heat isalso essential to provide the required degree of expansion of theparticles, and the maximum development of their ahsorhing etiicicncy toinsure perfect impregnation of the particles by their binder, as Well asto insure substantial reduction in the latters quantity and consistency,in coinbination with simultaneous fixture of the graded particles inhorizontal layers thereof. :tor the purpose or" securing their verticalpositions under tratlic at right angle thereto, upon which element alonethe life of natural woodblock pavements is recognized to depend.

llhile l appreciate the fact that such heat will result involatilization oi the essential oils in the bitumen, l have discoveredthat, as an example, the artificial asphalts adaptable to incorporationwith sand and stonev in paving structures, contain a prohibitivequantity of such oils for use wit tvoocy particles, because of mydiscovery of the fact that to the extent the oily constituent isincreased the bonding value of the bitumen is lessened, and that oilwill not bind Woody particles, but on the contrary, seriously interfereseven with their own me chanical clasp with each other. I have discoveredthat when surrounded by an excessive quantity of the bitumen. theparticles, when inclosed in a vacuous space, Will, even in the presenceof such oxygen as is es.- pelled from the decomposing cellular tissue oiparticles, (which oxygen is, as quickly as formed, expelled from thechamber) not ignite or carbonize when exposed to as high as 500 degreesFahn, and that while. it this heat is sustained a sutficient length oftime, the preserving and binding value of the bitumen Will be therehydestroyed, yet

' in my process such heat is applied in predetermined degree withespecial regard to that required to reduce the oily constituent of thebitumen, and its normal fluidity "from an excess thereo'l to the exactconsistency for practical use with Woody particles in the completedproduct.

in my search for means of retaining essential ductility of bituminouscompounds which the oily constituent is reduced to discovered t nepresence of the excessive quantity thereof, when first L lxed with theparticles, mar, addition to providing the employed means for avoidingcarhonization oi the WOOCl and bitumen hy severe heat, he advantageously utilized, in combination with such heat, and the steam inevolution, when super-heated. a means "for absorbing pure sulfur, addedin practical quantity to the other ingredients of my composition Wniiemixing: thorn; and l have iurther discovered that While in the use ofnatural sulfur-bearing asphalts, but a comparatively srnall quantity oipure sulfur should he added to mixture, yet in the use of artificialasphalts the addition of this ingredient results in increased ductilityof bitumen thereby made more cementitious in its rela tion to needyparticles, and less affectable hy the heat ofsuminer or the cold ofWinter than any bituminous compound used for paving of which I haveknowledge: provided, however, the excessive quantity of oily constituentis first present to act, under the influence of severe heat, as theabsorbing medium or" the sulfur, to be then partially eliminated byvolatilization thereof.

in a further modification of my process. and as distinguished from itsuse in fornr ing paving structures, 1 have also discovered that in anymanufacture of Water-prooted building blocks, columns and othersubstitutes for timbers, in which no bitumen is used, the naturalparticles contain much,

in addition to their libers, that is practically usable in forming suchcompositions,viz.. most of the hard-Woods, such as beech. maple, oak andthe like, contain a large percentage of pyroligneous acids, which inpractice it have separated from the WOOCl by destructive distillation ofits cellular tissue, in the manner heretofore described. when combined,as they do, with sulfur, in the presence of the steam expelled from thewood, hydrated sulfuric acid is formed, which, in contact with casein insolution, produces a gummy mass of cernentitious va ue. Because of thesimultaneous enlargement of, and the incidental creation of vacua Withinthe pores of the particles, this substance is absorbed at once by thepores. it then this is done in the presence of approximately 5G0 degreesFahn, l have discovered that the particles are thoroughly waterproofed,and are ready to be compressed into shape in the manner hereinafterdescribed. ln fact 'i have in practice impregnated the pores of hardwoodwith a solution oi sulfur and crude pyroligneous acid, and found thatthe heating thereof, in cacao, to a temperature of approximately 500degrees ahr., resulted in perfect and permanent Waterproofing oi theWood.

a further modification of my invention iireprooling solrnfiions anylei-own conneonate sistence may be added before or after the mass is soimpregnated.

In a further modification of my invention, the building or pavingstructures may be reinforced by wire mesh, twisted steel rods, or otherreinforcing matter placed within the structure before compressionthereof,

It has been heretofore proposed to cause particles in paving aggregatesbound with bituminous or other compounds tolie flat on horizontalrelation to each other and to the earth, and it has been recognized thatif such woody particles could be bound in a preserved state in suchmanner that only the ends of the fibers could be presented to the actionof traiiic, a muchmore durable product would" result from the tendencyof the particles tomat under the influence of such wear with lesslikelihood of disturbing, the bond between the particles touched bytraffic than if the fibers were prescnt in the mass in variouslyinclined positions.

The horizontal fixture of my particles in paving structures is insuredby (a) the irregular length and breadth exceeding their uniformthickness, (6) their beveled, tattcred edges, (0) consequently theirnatural inclination-t0 lie flat in a quantity of fluid of theconsistency of water sufiicient to float them until such flat,horizontal positions are assumed, (d) vibratory motion of theircontainer during setting of the particles; (e) together with the actionof the severe vacuum within which they are so positioned, and the entireabsence of pressure, atmospherically or otherwise, until the mass ismechanically compressed without disturbing the relative location of theparticles.

A composition of such particles mixed with bitumen is more practically,than otherwise, compressed to a thickness of only two inches. If greaterdepth of the product is desired, such increased depth should be formedby layers of the completed product cemented together. structure is ofthe form of ordinary sheet asphalt, I prefer, for the sake of horizontalor vertical presentation of all the particles to the action of trafiic,as the case may be, to out the material into blocks or slabs 36"x36",

set dodge-fashion, in the one case, and to cut the material into blocks2"x2"x9" in the other case, and I have discovered that when, beforeplacing, the blocks are painted at their edges with a sufiicientquantity of the same cementing agency as that with which the particlesare bound together, the blocks will adhere to each other so intimately,within a short time after being subjected to trafiic, as to formsubstantially a monolithic pavement, the joints in which are notdiscernible to the naked eye.

In a modified procedure I mix predetermined percentages of bitumen andnormal woody particles of various sizes, such as When thepavementdescribed in my copen application Serial No. 874934, undersustained heat suit ficient to destroy the cellular tissue,- sap anddischarge the distillates thereof and moisture from the mixer duringdevelopment of the absorbing capacity and impregnation of the particlespores by the bitumen and I lay the material on the previously preparedroad base hot, gradually cool and contract it, and. then compress thesame, during contraction, into a sheet pavement in the mannor in whichsheet asphalt is laid,

I have discovered that the popular impression that the hotter, andconsequently, the softer the mass is, the denser it canbe compressed,when hot, is entirely erroneous as related to fibrous compositions. Evenin mineral compositions mixed with hot bitumen the elements of expansionand contraction of the bitumen itself are not sutliciently guardedagainst in this regard, whereas with wood fiber, I have discovered thatthe particles do not reach the limit of their con;

traction until cold, and while heat is essential to render the masssufiiciently plastic to rake, spread, or otherwise handle in forming apaving structure, it may be, after he ing so formed, compressedpreferably when thoroughly cooled to atmospheric temperature, thancompressed when hot. i have also discovered that lack of regard for, and

insuiiicient means to avoid the entrapping.

of air and gas bubbles within the mass during compression has beenresponsible for the prcsence'of a rohibitive volume of voids in thecomplete product. I have discovered that plunger compression of suchmaterial in any other than an open mold is wholly impracticable, whileplungcr compression of such material in any mold is ineficient, in thatin every case it seals the top and bottom of the mass before releasingthe gas and air in its center, or giving a full opportunity to theingredients to contract from abnormal expansion caused by their heat. Ihave found that even the to and bottom roller compression. adopted y meas the most practicable, in an open mold, is accompanied by unfavorableelements which are necessarily guarded against in the formation of aperfect product: viz., the tendency of such compression 'of the warm,plastic mass, to increase its sheet area at the sacrifice of verticaldensity, as well asthe slight inclination of all particles toward onedirection. In my process the mass in the first instance is conveyed,independent of the forwarding influence of the rollers, between them, bya foraminated ma inclosed at its surface with an end and sidescompleting the container for the material; after h sufficientlycompressed and cooled the material passes onto a shelf inclosed at itssides, re-

did

cues for forward motion of the sheet bc- 1,2e5,eee I thereof, and Fig. 7is a side elevation in section of a hydraulic press.

Referring to the drawings by numerals, in carrying out my invention, thewood is sheared into sheets from the log 1 anchored by clamp 1, revolvedby pulley l driven by belt 1", the lo being in engagement with fixedknife 2. he sheets 3, of the desired thickness, are deposited intohopper 4 of shredding machine 4, in which the sheets are reduced toparticles by shredding mechanism operated by pulley 4 driven by belt 4".The particles are conducted from the shreddin machine through chute 4and depositef onto screen 5, within which is spread mesh which willpermit the passage of particles of the size 1"xi graduating down tothose of an average size corresponding with the thickness of the raggededges of the particles. Screen 5 is slightly inclined from horizontaland is designed to be given a vibratory motion, which will cause theparticles which will not pass its mesh to be worked to the top of thescreen and deposited into re-shredding machine 6, operated by pulley 6driven by belt 6, in which these larger particles are cut into smallersizes and returned to screen 5 by belt conveyer 7 after being depositedthrough chute 6 into container 7. Screens 5 and 5 preferably containmesh which will permit of the passage, first, of particles in size f'xfgraduating downwardly, and secondly, of particles in size lfx graduatingdownwardly, those failing to pass screens 5 and 5 being conducted bytheir inclination from horizontal into measuring boxes 8*, and being inthe minority of the mass; those passing screen 5 shall pass screen 5 inmajor proportion of the mass. and are likewise conducted to measuringbox 8 as shown. The particles are then measured in predeterminedquantities of each of the several grades from the largest. viz.. -}x3,-by the thickness of the sheets. in regular descending gradations down tothe size gxk" 40% thereof; those from %"x{;, to the thickness thereof50%, while approximately 10% of smaller particles in the mass is securedas a result of adjusting the shredding machine to produce practicallythis quantity in the shredding of the sheets into particles. Theparticles are then mixed in the common chute 8, by which they areconducted to a measuring container 11, through which in proportions inrelation to that of the impregnatingbinder yet to be referred to, theparticles are discharged into mixing apparatus 12, through gate 12". Theimpregnatingbinder hereinabove described, is preferably heated tosufficient fluidity in kettle 9, measured in predetermined proportion inrelation to the proportion of particles, as described, in measuringkettle 10, and discharged through cock 10, simultaneously with theparticles, into the mixer 12, through pipe 10", or otherwise. Chamber 12is nested within oven 13, surrounding substantially three-fourths of themixin chamber 12, in which oven heat is supplie by a furnace, theheat-from which preferably generated by burning gas, or oil, isconducted by exhaust fan 13 in stack 13, so as to artially surround theinclosed section of the mixer 12, and at the point l3 be sucked into andthrough the inner chamber of mixer 12, in direct contact with thecomposition therein being agitated and mixed by the operation ofagitating blades 12 anchored to central shaft 12 revolved by pulley 12driven by belt 12. The mouth of mixer 12 extends from a point in theshell of said mixer extending externally of the oven 13, which mouth 12is equipped with air-tight gate 14", in housing 14 toward which thematerial in the mixer 12 is conducted by the peculiar shape of theagitating blades 12 Gate 14 may be operated by hand, care being takenthat at least one-fourth of the space within the housing 14 is filledwith the material when the gate is turned to admit the material withinimpregnating chamber 14. If, in accord with the modification of theinvention hereinabove described the composition is to be laid inmonolithic sheet form and not manufactured into blocks, the material is,at this point deposited through gate 14 onto the previously preparedbase of the roadway, but in this event, the material is permitted toremain in drum mixer 12 until the particles have exhausted theirabsorbing capacity and become impregnated with the bitumen in the mannerdescribed. Upon reaching this chamber the mass is dropped onto bafiieplate 14, the first of a series thereof, anchored in an inclinedposition within chamber 14, to which plates may be attached off-setswhich act to turn the mass, and to expose the particles thereof to theheat and vacuum influences within chamber 14 hereinafter described, inthe fall of the material from the top of the chamber 14 to its bottom.Between the battle-plates, as shown, endless conveyers 14 operated bycog or sprocket connection with common shaft 14 are revolved on rollers14, 14", to which conveyers are attached buckets 14 14 designed to pickup the material at the bottom of the chamber 14, lift it to its top anddrop it through the heated vacuum of the chamber, over the baffles 14 tothe bottom of the chamber in a sufiicient number of such operations toexpose each of the particles to the inflcnce of the heat and vacuumwithin the chamber 14, hereinafter described, for the purposeshereinabove set forth.

Chamber 14 is preferably constructed of heavy steel, and its lowercurvature incnsed Withiniirebriclr 15". ;t is preferably hosted by twoturner-es the heat from which converge at its longitudinal center and isexhausted through stuck 15 Chamber 1% is partially nested Within thefurnaces 15 15 and shell 15, 15., within which turnaces 15*- snysuitable fuel may be deposited through doors to l? and burned to heatthe contents of chamber it to approximately 500 degrees elir. Exhauststack i l? leading from chamber 1% to condenser 1 is equipped with epowerful exhaust fan M in housing l l designed to create substantialvacuum Within chamber 14. The operation of the shore mechanism, and thesubjection ot the ingredients to the influences mentioned, therein,results in the maximum enlargernent of the particles, and expansion oftheir pores, the complete change in character of the matter theretot'oreforming its sap, cellular tissue and moisture, and in its extrac tionand removal from the particles, the development of maximum absorbingeiiiciency ot the pores, and their complete impregnation with bitumenpresent and surrounding them in excessive quantity, and also results inthe reduction of the oily constituent oi: the bitumen, to render thebitumen of pine ticsl plasticity and binding value in the completedproduct, as Well as the reduction of the plastic bitumen to a state ofextreme fluidity, in which condition it, together with the particleswhich it surrounds, is deposited Within chamber i l onto endlessconveyer 16', which conveyor is forsniinuted and is reyol ed by cog orsprocket Wheel 16 (shown in 8} around drums 16 -46 Conipressor rollers16 are re ol'ved by the action of their axles extending through thewells or chamber is and oven 15, in air tight bearings, and are anchoredin retaining bearings, Within which they revolve, riveted to the insidewalls chamber H -While compressor-rollers 16 are adjustable bymanipulation in such manner as to regulate the lust pressure gi en'tothe mass before emission from chamber 14-, the series of compressionsgiven by all of these rollers, revolving inversely us to conveyor 16",0t reciprocating size, speed and direction, being designed to expressfrom the abnormally enlarged pores of the heated particle lhe e1; cessquantity of bitumen hereinabore referred to, leaving Within the pores ofthe particles as they emerge from chamber 1% an insui'hcient quantity ofsuch bitumen to fill there, but sutlicient, in their subsequentlycontracted state. to completely fill them, to coat them, to till thecompressed voids be tween the particles and to bind them to each other.The bitumen expressed in the compression just referred to isprecipitated into the bot-torn chernber "ll, inclined downwardly at thispoint, toward, and is emitted through, outlet pipe 16 for use us aby-prod not. 16 is s men-hole for use in repairing the mechanism Withinchamber 1%. space between rollers 16 while norrnslly opened, iscompletely closed and air-tight by reason of the severe compressionorthe mass between the rollers at this point. The

products of distillation, us well as the fumes from the heating bitumenconducted through exhaust pipe l to condenser Where they are entrappedand reclaimed to be subsequently used as lay-products.

For at distance of approximately sir. feet from the innermost end ofconveyor 16* the V ioruinineted belt thereof is by proper mechanism,given a cider-rise vibratory motion, the material falling thereupon atthis point being inclosed by an end piece and two sides of steelconstruction, whereupon by such yibrstion and shaking of the conveyor,before tity.

Endless belt 16 extends through the walls of chamber is and oven 15 andbeyond and within cooling chamber 17 immediately c joining, in which nohost is present other than that arising from the hot mess coir reyedthereinto by conveyor 16. Cooling chamber 17 is also equipped withpowerful enhsust an 1'2 operated by pulley 17 in engagement with belt17, for creating and maintaining "Within chamber 1? substantinl vacuum,to prevent ignition of the hot mass before being surliciently reduced intemperature. Within chamber 1'? the moss is further compressed byrollers 1'? Without disturbance of the relative positions of the psrtices Within it, and the material is de signed to remain Within saidchamber 17,

in its course through it, a sufiicient length of time to reduce thetemperature to approxiinst-ely 200 Feband the depth of the mess toapproximately ll before emission through its mouth 17 which is closed bythe passage of riatericl therethrough in being: compressed at that pointto the thickness of approximately l.

ll hereupon compression continues, at at niospheric temperature, by acontinuation of endless belt 16 through two sided trough 18, andreciprocating rollers 18 18 which serve to reduce the thiclrness toapproximutely 3-5; by the time the mess is it proximately 150 degr es lehri, when the point 18* the forsniineted conveyor turns on drurn 16leading toward chamber 14. Referring to the enlarged detail, Fig. 8, 18designates a stationary trough of preferably steel construction,immediately next to the inversely operating rollers 18 18 interveningbetween endless conveyer 16 and trough 18. The material being conductedto the rollers 18 by the operation of endless conveyer 16", is ofsufficient solidity to bond its particles together to be pulled throughand between rollers 18 by their revolving action, much the same as acloth is pulled through the space intervening between the rollers of aclothes Wringer. Rollers 18 are of exactly the same circumference,revolved by the mechanism more in detail shown in Fig. 7, in which 18designates the sides to the trough, 18 the rollers referred to, 18 cogwheels which mesh with each other in reciprocating action, driven bybevel cogs 18 18 connected with suitable power. Longitudinally of therollers 18* a knifelike blade 18 extends the length thereof, and ispreferably of heavy construction, eX tending at right angles to thecenter of the rollers 15 in depth. Rollers 18 are each preferably 36 incircumference and are so revolved that the knives 18 18 will converge asthey pass each other not more than apart in cutting the sheet as itpasses through the rollers 18 which are designed to further compress thematerial from 3% to 3" in depth. The material when first compressed inchamber 14 is designed to be retained by the two sides of the troughcontaining conveyer 16*, which two sides are 36 apart, so that theblocks when first cut by the knives 18 shall be of the size 36X36x3". Bythe pressure of material behind them the blocks are pushed forward ontrough 18 until they reach a conveyer passing between compressionrollers revolved in a direction at right angles to rollers 18, whichconveyer is designed to move in a direction at right angles to trough18, in which latter operation the blocks are further compressed toapproximately 2% in thickness and at the same time are cut as in theformer manner described to a size 18"x36. The blocks are then conveyedto an endless conveyer which moves them in the reverse direction to thatin which they were conducted when first cut into blocks, and are in thisoperation again cut into sizes 18x9 inches and compressed toapproximately 2% in thickness. The blocks, while still retained in atrough 36 wide, but therein fitted together, are rolled in a directionthe reverse to that in which they were conveyed when out the secondtime. and then compressed to approximately 21', the speed of theconveyers and the time elapsing between that at which they emerged fromcooling chamber 17 until reduced to the thickness of 2 1" beingsufficient to cool the mass throughout its depth to that of atmospherietemperature, whereupon the blocks are placed in a mold and subjected tohydraulic pressure toreduce their thickness to 2". It is obvious thatthe blocks when placed in this mold may be of any practical size but inpractice I prefer that five such blocks each of the. size 18X9x2;lbeplaced adjoining each other in a mold of an exact size to contain them.In the described cutting of the sheet into blocks the blades attached tothe compressor rollers are at each revolution thereof dampened withwater and coated with Portland cement or other dust, which thereafterprevents the sticking together of the blocks during subsequentcompression together, this being primarily due to the severance of thesuperior bond between the particles in the various blocks at the pointof cutting. Likewise the surfaces of all compressor rollers except thosein chambers 14 and 17 are, as shown by the water and dust containers 18in Figs. 7 and 8 s0 dampened and dusted to avoid sticking, or picking upof the mass during compression and handling. Likewise the insidesurfaces of the mold in the hydraulic press are so treated before theblocks are therein placed.

It is obvious that the blocks when reduced to the size 9x18x2" may be,while being so reduced from their thickness of 23;" to 2", in thehydraulic press, or afterward, further cut, by known mechanism, under hydraulic or other pressure, into blocks of smaller size. In practice Iprefer to out one block 9x18x2 into eight blocks 2"x2x9 in oneoperation, an allowance of one inch being made for further lateralcompression, and space for the knife blades intervening in thisoperation.

It is also obvious that the material thus produced may be, byinterfering with the longitudinal positions of the particles, carted toa roadway and laid while still hot after passing through the cooler 17,as hereinbefore set forth; or the mass may be compressed into slabs ofany size and thickness not exceeding 2 in the manner herein described,or the material may be cooled to atmospheric temperature upon beingemitted from cooler 17, stored and then reheated at point ofconstruction for use in being spread and rolled on a previously preparedroad base in the manner in which mixtures of asphalt and sand have beenheretofore laid.

I claim:

1. The process of manufacturing a composition of matter for pavingpurposes consisting in shearing, then shredding wood into beveled,ragged edged particles of substantially uniform thickness of notexceeding 3; and of irregular lengths and breadths graduating indescending scale of sizes from those approximately 1"xi to {'xt", IHB2LSuring and mixing 40% thereof with 50% particles,

of those in sizes graded from {WK-l, to a culoe whose diameter is thethickness of the mixed with 10% of sizes graded from that or" thelargest cube to those of dimensions corresponding to the averagethickness of the ragged edges of the particles; then mining particles incacao With a preheated bitumen of ap oronimately 76* standardpenetration, in quantity approximately 50% in excess of that required inthe completed product; then agitating the minture while strongly heateda predetermined length or" time to partially volatilize the oil ol thebitumen to reduce such penetration o approximately to, to abnormallyenlarge he particles and to separate and expel from their ennandcd oresall moisture, sap, essences, cellular tissue and pulpy matter, bydestructive distillation thereof, and; by the i influence of the tancreating the vacuum, EX-

polling from the chamber containing there, all such products, togetherWith the fumes lrom the heated bitumen, simultaneously imthe expandedpores of the pan icles, by their absorption of the melted loitumen; thendraining superheated bitumen through the particles, during vilorationof" their container, to settle the particles horizontally; then, whenstill heated to suiticient fluidity, expressing the excess bitumen fromthe particles, retaining in their expandpores merely enough tocompletely fill them ivlen subsequently contracted, to coat t m, to fillthe voids between the particles en finally compressed, and to bind themLO each. other; then cooling the mass and gradually compressing the sameinto shape, during and after contraction of the ingredients,substantially as described.

2. The process of manufacturing composins in which graded sizes of fiatparticles uniform thickness with loeveled ragged s are mixed with sulfurand then, under nlluence of heat, with an excessive quanof preheatedbitumen oi oily constituency; then e osing all parts oi the mixture tothe ini uence of strong heat in mono to reduce the volume of oilyconstitutent in the oitumen, during its absorption of the sulfur, and toreduce the situmen to a state of extreme lluidity, simultaneously enlarging, abnormally, the particles, and expelling therefrom, and from thechamber containing them, all moisture, essences and cellular tissue loydestructive distillation thereof, and impregnating the expanded poreswith, y their absorption of, the bitumen, then drainins; the'excess ofbitumen through the par ticles during vibration of their container, toset or settle the particles horizontally of the earth; then expressing apredetermined quantity of bitumen from the mass hy compression thereof,then removing the mass from the i once of heat, and partially compressir,he satire While cooling in cacao;

nen exposing the mass to atmospheric oeratare and While further cooling,

.L 9 ng' series or reverse and transverse ro r compressions at itsbottom and top suri a 5 then, when cold, rurther reducing its tniclrnessby compression, and simultaneor l 1 ting same into blocks, substantiallydescribed.

3. The method of producing tion in which 'aded sizes 0:. edges are mixedto the influence of a temperature 0 matcly 500 degrees F in @656250normally enlarge the particles and to rate all moisture, sap,pyroligneous and pulp from their expanded pores lo structivedistillation of the products, taneously, by sullicient agitation, e thobitumen to the absorbing capacity 0 expanded Woody narticles during evoof dry, superheated steam from removing, through the agency cr vacuum,the unabsorbed fumes and arising therefrom; then. cooling the m cact /oand during alter contraction the particles, compressing the same iShane, substantially as described.

l. A method oi producing a coinnosit" of graded Woody particles mined ina chi ,1.- loer "with. bitumen While stron ly sufficient in degree toabnormally the particles ct Wood and to separate l moisture, essences,pyroligneous, and otacids and nulp therefrom; agitati mass in thechamber to the his to the ahsorhinr; capacity the Woody 1c ticles;impregnating the expanded pores c. the particles by their absorption, oservative-binder so formed, remov" the clianibercontaining it allunabsoioed steam and fumes arising from the tuen exposing the mass toatmospheric term perature, and then compressing the see c into shapeduring and alter contrac ion r the particles, substantially asdescribed,

5. The method of producing a no structure of monolithic character inrad-ed sizes of flat Woody particles o5 un orm thickness, but withragged edges a e 1 5 ixed, under the influence of heat withre-cetermined quantity of preheated loitumen, and then subjected tosuficient heat to abnormally enlarge the pores of the ticles and toexpel therefrom all moislare, essences and cellular tissue loydestructive distillation thereof, the particles being si multaneouslyimpregnated by their absorption of the molten bitumen; the partiallycompressing the mass when spread upon previously prepared road case,during cooling and contracting of the ingredients, to substantiallytitty per cent, of the uncontracted, uncompr when so spread, l

im losame may at assume of the sheet being had by transverse action ofthe rollers thereon after the mass is thoroughly cooled, substantiallyas described.

6. A fibrous composition consisting of woody particles of uniformthickness and irregular lengths and breadths, impre nated and bound bybitumen in planes su stantially parallel to each other.

7. A fibrous composition consisting in graded sizes of Woody particlesof uniform thickness and irregular lengths and breadths, with beveledand ragged edges,

from which particles have been removed sap, cellular tissue andmoisture, impregnated with bitumen, and compressed into shape,substantially as described.

8. A fibrous composition consisting of woody particles With beveled andragged edges, of uniform thickness, shredded into various lengths andbreadths graduating in irregular area varying from 1X3;" down todimensions corresponding with the thickness of the particles, mixed inpredetermined quantities in regularly descending gradations from thelargest to those approximately ,"x forty per cent; those from {k -t todimensions corresponding with the thickness thereof, those of particlesin size graduating from all of the greatest thickness to those ofdimensions corresponding to the thickness of the rag ed edges of theparticles, 10%, from which particles have been removed sap, cellulartissue and moisture, impregnated With a cementitious Wood preservativeand compressed into shape substantially as described.

9. A fibrous composition consisting in graded Woody particles of uniformthickness and irregular lengths and breadths with beveled and raggededges, from which particles have been removed sap, cellular tissue andmoisture, coated and impregnated With a Wood preservative ofcementitious nature and compressed into shape.

10. A paving block of fibrous composition consisting in graded woodyparticles of uniform thickness and irregular lengths and breadths, withbeveled and ragged edges, from wvhich particles have been removed sap,cellular tissue and moisture, impregnated and bound with bitumen inplanes substantially parallel to each other, and cut so that its breadthis that of the thickness of the compressed sheet of which it formed apart.

11. The method of producing a monolithic paving structure, consisting inchipping Wood into particles of various shapes and graded sizes; thencoating the particles in a drum with preheated bitumen, through whichbitumen under sustained heat and during agitation of the mass, thecellular tissue, sap and moisture in the particles are destructivelydistilled and then expelled from the drum, simultaneously exhausting theabsorbin capacity of the particles with the heated itumen; thendepositing the mass onto a previously prepared road base and compressingthe same into shape.

12. A monolithic pavement structure consisting in graded Woody particlesof uniform thickness, and-irregular lengths and breadths, from whichhave been removed sap, cellular tissue and moisture, impregnated andcoated With a cementitious preservative and compressed into shape.

In testimony whereof I have atiixed my signature in the presence of tWoWitnesses, the twenty-second day of January, 1916.

GEORGE A. HENDERSON.

Witnesses L. J WVHITE, C. W. ZERKLE.

live centa esoli;by ddrcaatng the commissioner 'tls' Worthington, D. Q.

